passing variables during checkout

More in the saga of adding fields to the checkout...

I've successfully added fields to the checkout process. And at the end of the process they are being added to the database.

However, when I put data in the fields, continue with checkout, then hit the back button, the contents of the fields disappear. But I see that the contents of the Comments field are retained.

I am assuming that there are hidden fields somewhere. And they are hidden well! Because I can't find them!!! LOL

I want the contents of these additional fields to be retained too.

Can anyone help?

Thanks!
K

PS
To see this hacking in action visit: http://www.laudercompany.com/orderonline
We've added AJAX functionality to preview imprint specs, and are adding an image upload feature to the checkout process.

As of this post this is not a live store. I will update this thread when the store is live. Once it is live, please do not post test orders. Thanks. K